In the interest of completeness - You actually aren't that far off. You could use a "Custom Behavior", which in this situation is more work; but I have always found when others on the Forum expand the possibilities, sooner or later that technique shows up as useful in some other scenario.

In the "Scene Inspector" I added a "Custom Behavior" named "newURLLoc"

which is one step too far in my opinion. as you have to create the custom behaviour and still call it with Javascript. Whereas you are just using one line of Javascript to call "window.open" but it does highlight another way to do it. I know you mentioned it could be more work. In fact it could be an extension.

thanks, both of you. this goes a long way in helping me to understand the overall structures. this is my first Hype piece—adding onto a project I started in '15 with Adobe Edge Animate.

the original EA pieces were assembled as several separate presentations connected via a menu document, and controlled via the arrow keys.

arrow-up opens the index file if the presenter gets lost, arrow-down goes to a menu file with all the individual presentations, and left/right go back and forth inside the presentation. this isn't terribly different from what I created with EA, but just enough to be a little confusing. got it now. thanks again.